Air droppable apparatus



Sept. 1; 1970 B. CAIN AIR'DROPPABLE APPARATUS 2 Sheets-Sheet 1 Filed March 12, 1969 INVENTOR. Blanchard Cain BY 777M, awwmfgw Sept. 1, 1970 5, CNN 7 3,526,376

AIR DRQPPABLE APE ARATUS Filed March 12, 1969 $h00i5-5h0ut FIG 2- INVENTOR. Blanchard Cain BY 777/00, die/M12, 5 762mm United States Patent 3,526,376 AIR DROPPABLE APPARATUS Blanchard Cain, Scottsdale, Ariz., assignor to Motorola, Inc., Franklin Park, 111., a corporation of Illinois Filed Mar. 12, 1969, Ser. No. 806,581 Int. Cl. B64d 1/02 US. Cl. 244-138 8 Claims ABSTRACT OF THE 'DISCLOSURE An air drop radio beacon wherein the housing is provided with auto-rotation means and contains a series of weights attached to elastic lines. During the travel of the radio beacon through the atmosphere, the weights are centrifugally deployed about the beacon and contribute to the stability thereof as well as providing tree top retention by entanglement with the ground cover.

BACKGROUND OF THE INVENTION The present invention relates to air drop packages of the type containing radio beacons and, more particularly, to air drop packages adapted to be retained by the ground cover at an above ground level position.

Air droppable apparatus is presently 'being utilized to establish radio communication links for a radio beacon in rescue operation or to mark a particular area wherein activity has been observed. Since in many parts of the world the ground cover or foliage is exceedingly dense and high, it has been found that conventional air drop packages which are designed to penetrate the ground and remain in an upright position suffer from the fact that the ground cover greatly attenuates the transmitted and/ or received radio signals. Further, the fact that the air drop package penetrates through the ground cover to the ground renders it likely that the physical presence of the package is readily detected. In addition, successful use of air drop packages has heretofore required that the package and associated penetration device, i.e., spike or spear, be designed in accordance with the altitude and speed of the plane carrying it. The package normally contains relatively fragile electronic apparatus and, consequently, shock absorbing means or parachutes are normally provided to control the impact shock generated when the package encounters the ground.

Thus, a need has arisen for an air drop package which is retained by the ground cover in an oif-the-ground position. The present invention is directed to an air drop package which contains means for engaging the ground cover and thereby preventing the package from reaching ground level. Further, it is an object of this invention to provide the aforesaid engagement of the ground cover at a relatively low cost and weight while still providing a high degree of reliability. Still other objects are the provision of an air drop package which is suitable for transmitting radio signals in densely foliated areas and which is relatively undetectable by visual observation.

SUMMARY OF THE INVENTION The apparatus incorporating the present invention includes a housing for containing the radio beacon or similar electronic apparatus and auto-rotation means mounted thereon for imparting rotation to the housing as it travels through the atmosphere. The auto-rotation means, typically vanes angularly disposed on the outer surface of the housing, cause the housing to rotate about its central axis. In addition, a plurality of weights are contained within receiving passages provided in the housing. Each weight is attached to one end of at least one elastic flexible elongated retaining member. The opposing end of each retaining member is attached internally of the housing, preferably by biasing means which tend to retain the members within the housing when the air drop package is stationary or non-rotating.

The passageways containing the weights are provided at equally spaced locations about the outer surface of the housing. The rotation of the air drop package as it travels downwardly through the atmosphere results in the centrifugal force of the weights overcoming the biasing force tending to retain the elastic members in the housing. Consequently, the weights move radially out through the passageways from the housing. The centrifugal force of the weights rapidly exceeds the biasing force as the housing increases in rotation. After a short period of travel through the atmosphere, the weights are essentially symmetrically disposed about the housing at the end of the corresponding elastic retaining member. The retaining members are fully extended at this point in time. Since the passageways are equally spaced on the surface of the housing and the elastic members are made of equal length, the rotating weights are found to improve the stability and trajectory of the package as it travels through the atmosphere due in part to the gyroscopie effect provided by the moving weights.

When the air drop package falls to the level of the ground cover, the weights are rotating about the housing with the elastic members fully extended therefrom. The extended elastic members contact the ground cover and firmly engage their extremities since the rotating weights rotate "about the ground cover rather than the central axis of the housing. As a result, the downward travel of the package is arrested prior to its making contact with the ground. The elastic characteristic of the members provides the shock-absorbing function and thus reduces the likelihood of damage to the electrical apparatus contained within the housing. Further, the air drop package is retained in the preferred above ground position and the possibility of visual detection is reduced. In addition, the air drop package is located proximate to the edge of the ground cover so that the attenuating effects of the foliage on the transmitted signal are substantially reduced. Further features and advantages of the invention will become more readily apparent from the following detailed description of a specific embodiment when viewed in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an air drop package incorporating one embodiment of the present invention.

FIG. 2 is a partial side view in section of the weight retention assembly of one embodiment of the invention.

FIG. 3 is an end view of the embodiment of FIG. 2 showing the weights in the retracted position.

FIG. 4 is an end view of the embodiment of FIG. 2 showing the weights in the deployed position.

FIG. 5 isan end view of another embodiment of the invention showing the weights in a deployed position.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, an 'air drop radio beacon 10 is shown including a cylindrical housing 11 for containing the radio transmitting apparatus and any other additional cargo therein. Housing 11 is provided with a coupling section 12 located at its upper end. The coupling section is connected to weight deployment section 13 which in turn is connected to weight retention section 14. An antenna 15 is provided at the end of the radio beacon. As shown, the air drop radio beacon 10 is provided with a number of angularly disposed vanes 21 which impart rotation to the beacon when it travels through the atmosphere. While vanes 21 are shown in the present 3 embodiment, it will be apparent that many other types of auto-rotation means may be employed if desired.

The weight retention section 14 contains a number of apertures equally spaced about its surface. These apertures or passageways, totalling six in the embodiment shown, contain weights 19. Each Weight is provided with an elastic line 20 which extends outwardly of the passageway in retention section 14 and down to a corresponding aperture 17 in deployment section 13. The lines extend inwardly and the ends thereof are secured within section 13. When the radio beacon is dropped and travels through the atmosphere, it rotates about a central axis due to vanes 21, and this rotation results in the weights 19 moving outwardly from the retention passageways in section 14. The wei hts rotate about in a plane normal to the central axis of the beacon. The centrifugal force exerted by the weights on the elastic members results in the elastic members being placed in tension.

As will later be described in additional detail, the coupling section 12 contains a biasing means which tends to oppose the effect of the centrifugal force of the rotating weights. In addition, weight deployment section 13 is connected between coupling section 12 and weight retention section 14 in a manner which permits the relative rotation thereof. As a result, the centrifugal force of the weights tends to cause deployment section 13 to rotate about the central axis of the housing 11. This rotation of deployment section 13 results in additional lengths of the elastic lines 20 being fed from section 13 and the weights moving outwardly of the central axis of the housing 11. After a short interval, the centrifugal force of the weights is sufficient to overcome the biasing force provided by coupling section 12 and to draw the elastic lines out to their full length. As the air drop beacon continues to travel through the atmosphere, the rotation of the beacon ensures that the weights continue to travel in a path about the central axis of the housing. When the beacon enters the ground cover area, the weights cause the elastic line 20 to become entangled with the extremities of the ground cover and therefore prevent the beacon from reaching ground level. The elastic character of the lines 20 provides the shock absorbing feature necessary to protect the electronic apparatus contained in housing 11.

The construction of the weight retention assembly affixed to housing 11 is shown in further detail in the side view of FIG. 2. As shown, coupling section 12 includes cover plate 25 and extension member 26 attached thereto by threaded bolt 27. The extension member 26 extends into housing 11 of the assembled radio beacon and is attached thereto by suitable fastening means. The weight deployment section 13 includes outer sleeve 28 which contains the equally-spaced apertures 17 at the upper end thereof. In addition, section 13 includes base plate 29, bearing means 30, and central core section 31. The centrally located core section 31 contains a pin member 32 extending laterally therethrough. The inner ends of the elastic lines 20 are connected about the pin 32. Core section 31 is coupled to the top plate of bearing 30 by the upper portion of threaded fastener 27 As shown, the core section 31 is fastened to cover plate 25 of coupling section 12. Thus, core section 31, cover plate 25, and extension means 26 rotate as an integral part as the air drop radio beacon travels through the atmosphere. The bearing 30 between core section 31 and base plate 29 permits the outer sleeve 28 of deployment section 13 to rotate relative to the core section 31. Spring 33 contained in the space between flange 29 and cover plate 25 prevents the rotation of the outer sleeve 28 except when the centrifugal force of weights 19 exceeds the biasing force provided by the spring.

Apertures 17 are provided about the periphery of sleeve 28 in the upper section thereof. As mentioned previously, the apertures are equally spaced about the circumference of the sleeve. Threaded through each sleeve is an elastic line 20 which is wrapped about core element 31 and then brought inwardly thereof and fastened about pin 32.

The weight retention section 14 is shown fastened to core section 31 by means of central element 35. Central element 35 contains a recess 36 in the outwardly extending portion thereof for the attachment of a radio antenna. The central element 35 is fastened about its inner end to core element 31 and contains apertures 40 therein to permit the elastic lines 20 to extend from inside the core section 31 out to the chamber formed between sleeve 28 and the core section.

The ball retention housing 37 of section 14 is attached to central element 35 or may be formed as an integral part thereof. Bushing 38 is fastened by screws 39 to sleeve member 28 and is interposed between sections 13 and 14. Since the weight retention housing 14 is coupled directly to the housing 11 of the air drop beacon via the central core section and the threaded fastener, the entire weight retention section rotates with the housing. However, bushing 38 permits sleeve 28 to rotate relative to the retention section 14 and thereby enables the lines to be drawn outwardly from within section 13. The retention passageways 18 are contained in section 14 and initially hold the Weights 19.

When the entire assembly is attached to a housing of an air drop radio beacon preparatory to the drop, the weights are contained in section 14 although connected via lines 20 to section 13. The lines are coiled about central element 31 and the ends thereof are fed through apertures 40 in central element 35 to pin 32. At this time, the biasing force provided by spring 33 retains the lines in a coiled position. As the beacon travels through the atmosphere, the auto-rotation means on the housing 11 provide the rotation which causes the weights to leave the retention passageways. This is due to the centrifugal force urging the weights out of the passages. When the Weights are disposed outwardly of the retention assembly, the centrifugal force increases as the beacon travels through the atmosphere and overcomes the biasing force provided by springs 33, whereupon the sleeve 28 rotates and in effect lines 20 become uncoiled from core element 31. As a result, the balls move outwardly until the lines are fully extended. The weights continue to rotate with the air drop beacon until they encounter an obstacle such as the extremities of the ground cover. At this point, the lines become entangled with the ground cover and the beacon is retained in a position above ground level. The gyroscopic effect of the weights rotating outwardly of the air drop radio beacon has been found to impart stability to the beacon and reduces the possibility of end-over-end travel or tumbling as the beacon drops.

The weight retention section 14 is shown in the end view of FIG. 3 with the weights in their corresponding passageways. After the initial rotation which results in the weights leaving the passageways, the pattern assumed by the weights as the air drop beacon travels through the atmosphere is determined by the configuration of the elastic lines. One such configuration is shown in FIG. 4, wherein the weights are deployed by elastic lines extending radially outwardly of the beacon 10. A second embodiment utilizes interconnected elastic lines to further increase the probability of entanglement with the ground cover. It shall be noted that in this embodiment, each elastic line emanating from the housing 10 is coupled to two weights. Thus, a loop is formed which promotes the snaring of the ground cover.

While the above description has referred to specific embodiments of the invention, it will be apparent that many modifications and variations may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. In air droppable apparatus of the type containing auto-rotation means mounted on the housing thereof to impart rotation about a central axis during descent, the improvement which comprises:

(a) a plurality of weights disposed symmetrically about said central axis;

(b) a like plurality of retaining means, each of which is coupled to at least one of said weights;

() a like plurality of weight-retaining passageways formed in said housing; each of said passageways retaining at least one of said weights prior to the rotation of said apparatus; and

(d) biasing means provided in said housing for urging said retaining means into said housing, the eifect of said biasing means being overridden by the force of said weights when the apparatus is rotating, said Weights extending outwardly during the descent of said apparatus to engage ground cover.

2. The improvement of claim 1 wherein said retaining means are flexible elastic lines.

3. The improvement of claim 2 wherein said housing contains a plurality of apertures symmetrically disposed about the central axis thereof, and said lines are connected through said apertures to said biasing means.

4. Air drop apparatus comprising:

(a) a cylindrical housing having a central axis;

(b) auto-rotation means mounted on said housing for imparting rotation thereto about said central axis;

(c) a plurality of weight retention passageways formed in said housing, said passageways being located symmetrically about said housing;

(d) a plurality of weights disposed symmetrically about said central axis; and

(e) a plurality of flexible elongated retaining members, each of said members being attached at one end to at least one weight, the other ends of said members being attached to said housing, the rotation of said housing about said central axis resulting in the symmetrical deployment of weights about said housing whereby said retaining members are in position to engage ground cover extremities during an air drop.

5. Air drop apparatus in accordance with claim 4 wherein said retaining members are attached internally of said housing and further comprising biasing means contained within said housing for urging said retaining members into said housing, the effect of said biasing means being overcome during the air drop whereby said weights are symmetrically deployed about said housing.

6. Air drop apparatus in accordance with claim 5 wherein said housing includes:

wherein said weight deployment section is rotatably coupled between the coupling section and the weight re tention section to permit relative rotation thereof when the weights are being symmetrically deployed during the air drop.

8. Air drop apparatus in accordance with claim 7 wherein said weight deployment section comprises:

(a) a core element connected between the weight retention section and the coupling section, the retaining members being attached to the core section; and

(b) an outer sleeve mounted between the coupling section and the weight retention assembly, said sleeve containing said apertures through which the retaining members pass, said core element and said sleeve being coupled to the coupling section and the biasing means thereon to permit relative rotation between said sleeve and core element whereby said weights are deployed when the retaining members are extended.

References Cited UNITED STATES PATENTS 9/1964 Barish 244-138 6/ 1965 Nielsen et al .244-138 11/1966 Icenbice et a1 244-138 8/1967 Girard 244-438 MILTON BUCHLER, Primary Examiner J. E. PITTENGER, Assistant Examiner 

